The Stovebolt Site Forums The Parking Lot Big Bolts 6400 correct axle

what is the correct rear axle for a 1948 , 6400, as the axle on the truck i,m buying appears to have been changed some years ago and as it is the truck doesn,t have a parking brake .. its a 6 stud rear yet the front is a 5 stud.
also what would the maximum gross weight for a 6400 be in kilograms as i reqiure the gross weight to complete some paperwork ,

many thanks ,mike,

A 48 model 6400 is usually rated at 16,000 lb gross weight, check the door tag. 7257 kilograms

Axle is usually GM, sometimes Rockwell, and 10 studs on a 7.25" bolt circle on the rear would be stock in any case.

what should the front axle be its got a 5 stud which i thought was original.
i cant check the I.D, plate as the truck is still 200+ miles away untill i get her home in the new year,,

i believe that it is ex,

texas independant oil refining co,
and came of a gentleman somewhere in the nevada desert three or four years ago, i think it could have been something like a drill rig truck or pipe carrier,,,its only chassis and cab at the moment .

Front axle should have 5 lugs also on a 7.25" bolt circle.

thanks grigg, it sounds like it has the correct front axle.
could the rear axle have been a two speed ?

i,m told the truck is a 6400 but is there any distinguishing items other than the tag plate that i could / should look out for ..

i,m now thinking that this truck has lost its two speed rear end for some unknown reason in the past
so a couple of questions,

1, how can i find out what the original rear end was ?
2, how could i source one ? and if needs be get it shipped from the states to the uk,,?

Some GMC's had 6 stud wheels. In any case it appears yours has been changed. I will look at my 48 shop manual and see if there is anything in the numbers that would indicate two speed axle.

For 48 the axle serial number would be located on the top of the carrier housing. For two speed on top of differentail carrier towards the rear and right. ratio standard single speed 6.17. Two speed 6.13 and 8.10. School bus option could be either6.13 0r 5.43. I didn't see anything on how to dechipher the numbers to indicate how it was equipped, that may be covered in the owners manual.

right i managed to get a friend to go and check ,to see if he could read the ,tag, on the axle.
turns out the ,tag, is good and clearly readable the following is what we now know.
ROCKWELL
TBBO 0005A
model F106 NXI
ser no, 058315
ratio 6.2:1
so the question now is where / what has this axle come from and how old is it.
i,v got some old books etc but nothing with this in..
also got the VIN no ,20RWH2292
thanks for all the help so far ..
mike,,

can any one identify what this rear axle is from and what year it is
i,v been looking on the net and come up blank.

i need to know what sort of parking brake it should have,, i suspect its of a truck with a trans brake,,